Japanese Patent Application Publication No. 2001-286122 (Patent Document 1) discloses a linear synchronous motor comprising a stator and a mover that linearly moves relative to the stator. The mover includes a direct drive shaft reciprocating in an axial direction and an array of permanent magnets including a plurality of permanent magnets fixed to the direct drive shaft. The stator includes a plurality of windings and a core unit with slots formed therein for respectively receiving the plurality of annular windings. The annular windings are each formed of an annularly wound winding conductor and are disposed to surround the direct drive shaft. The core unit is constituted from a plurality of core divided bodies assembled with each other in the axial direction. The core divided bodies are formed by cutting work. In this linear synchronous motor, the core divided bodies are combined with one another to form the core unit comprising a yoke. When the yoke is formed by combining the core divided bodies, however, shapes of the core divided bodies become complex. The manufacturing cost of the linear synchronous motor may be therefore increased. Further, when the core divided bodies are formed by cutting work, efficiency of the linear synchronous motor deteriorates due to eddy current generation.
Considering a loss due to an eddy current, preferably, a plurality of magnetic pole portions and the yoke are separately formed, and the magnetic pole portions are formed by laminating a plurality of magnetic steel plates.